Well let's see if it's something easy, noticed you are using csq on all of them, unless you change the tones for the pic, check your squelch setting see if it's below 3, or 5. If it's at 1 you may be getting interference in csq near electronic equipment or routers, car electric system in cab. Try a dummy test and put a tone in all the rx channels and see if the static remains, If it remains check your squelch settings and get it off 1 if you don't use a tone. 3 or 5 should be ideal 5 being default. If none of it fixes the issue it'll be the sj-180.